This paper presents a computational and theoretical investigation of the vacuum mechanosynthesis of di- amond on the clean C(110) surface from carbon dimer (C2) precursors positionally constrained throughout the reaction pathway by silicon- or germanium-doped triadamantane derivatives mounted on a scanning probe tip. Interactions between the dimer placement tools and the bare diamond C(110) surface are inves- tigated using Density Functional Theory (DFT) with generalized gradient approximation (GGA) by con- structing the reaction path potential energy profiles and analyzing ab initio molecular dynamics simulations. Similar methods are applied to study the energetics and kinetics of recharging the tool with acetylene. Molecular mechanics simulations on extended tool tips are carried out to elucidate the positional uncer- tainty of the carbon dimer due to thermal fluctuations, and the possibility of intermolecular dimerization and dehydrogenation of the dimer placement tools is explored.